Regulator.



H. A. LAYCOCK.

REGULATOR.

APPLlCATlON FILED OCT. 7, 1912.

M 1m 8 2 w D m H m a P f M 9 M IL 2 i w 6 6 1 1 I K TNEE'EES [N YENTDH9" M HARRY A.L.AY00 a ZZZ BIL/M UNITED STATES PATENT OFFIQE.

HARRY A. LAYCOCK, OF SCHENECTADY, NEW YORK, ASSIGNGR- TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

REGULATOR.

Specification of Letters Patent.

Patented Dec. 28, 1915.

Application filed October 7, 1912. Serial No. 724,228.

To all whom it may concern:

Be it known that I, HARRY A. LAYCOCK, residing at Schenectady, in thecounty of Schenectady, State of New York, have invented certain new anduseful Improve ments in Regulators, of which the following is aspecification.

My invention relates to voltage regulators of the resistance type. Suchregulators automatically control the voltage of a generator by cuttingresistance in and out of the field of the said generator or of anexciter for the same according to whether the voltage is too high or toolow. Regulators of this kind may be so damagedthat they will fail to cutin the regulating resistance and the voltage of the generator will thenreach an abnormal value. This may arise, for instance, by a break in thepressure wires or transformer leads which are connected across the lineat the point where the voltage is to be kept constant. These pressurewires extend back to the generator station and the current flowing inthe same is utilized to actuate a suitable mechanism which will cut asuitable resistance in or out of the field of the generator or eXciteraccording to whether the said current is high or low. Should thepressure wires be damaged by a break or other injury so that the currentflowing therein is lowered or reduced to zero the effect would be thatthe resistance controlled;

by the regulator would be continuously short circuited and the voltageof the generator would rise correspondingly. It is obvious thatconsiderable damage might ensue from an abnormal voltage thus produced.

The object of the present invention is to provide a means which will bebrought into operation upon the attainment in any manner of apredetermined abnormal voltage by the generator to reduce the saidvoltage to normal.

My invention consists in providing means in addition to the ordinaryregulating means which will be brought into operation upon theattainment of a predetermined abnormal voltage of the generator andwhich will insure a reduction of the generator voltage to a normalvalue. My invention comprises means for completely neutralizing theeffect of theregulator and for inserting in the circuit of the exciteror generator field a body of resistance which will reduce the voltage ofthe said generator to a normal value. Together with my invention I havethe operation of the regulator as before the damage to the first set ofpressure wires.

In my invention I prefer to utilize for the auxiliary resistance thesame rheostat as that ordinarily controlled by the regulator.

As the resistance ordinarily controlled by the regulator in the case ofsuch regulators as those disclosed in Tirrill Patents #725,800 and726,23 l is so high that the permanent inclusion of the same in thefield g of the exciter or generator would be apt to cause a shut-down. Iprovide means for short circuiting a portion of the said rheostatresistance when my safety device is brought into operation. 7

I have shown my invention in connection with a regulator such as thatlisclosed in Tirrill Patents #725,800 and #726,23l. In such a regulatorthe pressure wires are included in the circuit containing a solenoidwhich acts in conjunction with other elements to short circuit aresistance in the exciter field circuit when the voltage of thegenerator is too low and to cut said resist ance in when the voltage istoo high. As

applied to such a regulator my invention embodies means to cut theregulator out of circuit and to simultaneously short circuit a portionof the exciter field resistance when such an abnormal voltage occurs asmight; be occasioned by damage to the pressure Wires of said regulator.The arrangement is such that after the damage on the pressure wires hasbeen located and repaired the regulator may be readily reinserted in thecircuit.

In conjunction with the above described structure I preferably providemeans whereby,'upon the occurrence of the aforesaid abnormal voltage thedamaged pressure wires 1 are replaced in the regulator circuit byanother set. I also provide means whereby, instead of the regulatorbeing cut out, it may be made to act as before the break but with thenew pressure wires substituted for the old.

My invention will be more clearly understood by referring to the drawingwhich shows diagrammatically my invention embodied in a Tirrillregulator system.

In the drawing A is an alternating current generator which suppliescurrent to mains 1, 2.

E is an exciter which supplies current to the field 3 of the generatorA.

4 is the shunt field of the exciter E, and R is an adjustable resistancewhich is adapted to be connected in circuit therewith. The resistance Ris adapted to be cut in or out of the circuit of the exciter field 4 bymeans of a regulator of the type disclosed in the Tirrill Patent#726,234 hereinbefore referred to. As shown diagrammatically in thedrawing this regulator comprises a direct magnet lever (Z and analternating current magnet lever 64,, the former being actuated by thecoil D, O, which acts upon the core 5, This coil is connected across theeXciter mains and an adjustable resistance r may be included in the saidcircuit. Lever (Z, is fulcrumed at 6 and acts against a retractilespring 7. The end of said lever carries the contact 8. The alternatingcurrent lever a, is fulcrumed at 9 and carries at one end the core 10and at the other the counter-weight 11 and the contact 12. The core 10is adapted to be drawn downwardly a distance dependent upon the currentflowing in coil 13 which is connected at the desired point across themains leading from the generator A through pressure wires P P In thecircuit of said coil may be included the resistance R The contacts 8,12, control a circuit which includes the coils 14, 15 of the relaymagnet 16. This circuit is supplied with a suitable source of current,as by connecting it in shunt with the mains leading from the eXciter.The relay magnet upon being energized is adapted to attract the armature17 which is pivoted at 18 and which acts against the spring 19 to breakcontact at, 20 and thus include the resistance R in the field of theexciter. In order to prevent sparking the condenser C is provided.

The coil 21 is connected across the mains 1, 2. A suitable resistance B,may be included so as to lessen the current flowing through said coil.The coil 21 acts upon the core 22 the lower end of which works within adash pot 23. On the top of said core is a projecting pin 24. Immediatelyabove and in the path of travel of said pin is mounted the lever 25which is pivoted at 26 and held in the position shown by gravity.Normally supported by the end of said lever is the bar 27 of insulatingmaterial. To this bar is attached the rod 28 which engages with theguide 29 and to the lower end of which is attached an operating handle30. Above the bar 27 is mounted the spring contact 31 which is attachedto the block 32 and which may be regulated by the set-screw 33. Thecontact 31 engages with contact 34 when the bar 27 is in its uppermostposition, i. 6. when it is supported by the lever 25. On the lower faceof the bar 27 are mounted contacts 36, 37 which are adapted to engagecontacts 38, 39 when the bar 27 is released by the lever 25. Leadingfrom the contacts 36, 38 are conductors 40, 41, the former of which isin series with the eXciter field and the latter of which is connected toan intermediate resistance contact on the rheostat R. Connected to thecontacts 37, 39 are conductors 42, 43, the former of which connects withpressure wire P and the latter of which is connected to a pressure wireP Connected to the contacts 31 and 34 are conductors 44, 45, the formerof which is connected to the terminal corresponding to the minimumresistance of the rheostat R and the latter of which is connected to oneof the relay contacts 20.

- Switches 8, s are included in lead 41 and and cause the projection 24to abut against and lift the left-hand end of the lever 25. This willallow the bar 27 to drop thus separating the contacts 31, 34 andbringing together the contacts 36, 38 and-37, 39. \Vith the switches sand s in position shown in the drawing the efiect of this will be toopen the circuit between the rheostat RI and the short-circuitingcontacts 20 of the regulator and at the same time to includecontinuously in the circuit of the field 4 a predetermined portion ofthe resistance of said rheostat. This resistance will have the effect ofreducing the voltage of the main generator to normal but will not besuflicient to cause a shut-down. When the damage to the pressure wires PP has been located and fixed the regulator can be put back in circuit byraising the bar 27 by means of the handle 30 thus bringing together thecontacts 31, 34 and separating the contacts 36, 38 and 37, 39.

Should it be desired to allow the regulator to continue to act after thedamage to the pressure wires P, P this can be done by closing the switch8'. The regulator will then continue to act with the pressure wires P Psubstituted for wires P P by reason of the engagement of the contact 37with the contact 39. By opening the'switch S the entire field resistancemay be availed of and the regulator will operate to all intents andpurposes as before the damage to the pressure wires.

Various modifications of the structure described will suggest themselvesto those skilled in the art and are to be considered as coming withinthe scope of my invention as set forth in the following claim.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is The combination of a generator, an excitation system for saidgenerator, a resistance in said excitation system, a voltage regulatorarranged to short-circuit said resistance at intervals in order tocontrol its effective value, and means operative upon an abnormalincrease in the voltage delivered by said generator to break the circuitbetween the said regulator and said resistance and to short-circuit aportion of said resistance, so that the generator voltage is 10maintained at approximately its normal value.

In Witness whereof, I have hereunto set my hand this 4th day of October,1912.

HARRY A. LAYCOCK. Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). 0.

